In this paper we discuss the Sun Corridor concept and then restate the concept in the context of a transborder economic development. The Morrison Institute at Arizona State University coined the term Sun Corridor to describe developments in Flagstaff, Phoenix, Tucson and Nogales and the interstitial spaces between them. Applying the Morrison Institute’s methodology to the transborder mega-region we identify and describe the sub-regions, realms and nodes together with their internal and external challenges. In evaluating the benefits of the transborder Sun Corridor as a model for binational economic development we draw attention to legacies and lessons of an earlier model of binational crossborder collaboration in economic development known as the Arizon a - S onora Region. Arizona and Sonora have had a long tradition of functional and formal ties, and were among the first border states to strategize crossborder economic development within the North American Free Trade Agreement (NAFTA ) framework in the early 1990s.

JEL Classification: O2, F6, Z